WritersLogic Verifiable AI Agent Hub Tax Id Format API
The Tax Id Format API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for tax id format.
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OpenAPI Specification
openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Tax Id Format API
version: 2.0.0
description: Pay-per-call agents settled in USDC on Base via x402. Every response carries a signed provenance envelope.
contact:
name: WritersLogic
url: https://writerslogic.com/agents
email: agents@writerslogic.com
servers:
- url: https://agents.writerslogic.com
tags:
- name: Tax Id Format
paths:
/api/v1/tax-id-format:
post:
operationId: tax_id_format
summary: VAT / tax-id format and check digit (AT, BE, DE, DK, FI)
description: 'Checks the structure and check digit of up to 100 EU VAT numbers per call (Austria, Belgium, Germany, Denmark, Finland), for an agent about to put a supplier or customer VAT number on an invoice or into a record. Every other country answers unsupported rather than guessing a pattern. It never says whether the number is registered or active (that needs VIES or the national register), and a pass is not proof that the business exists.
Price: 0.005 USDC on Base (x402).'
x-x402-price-usdc: '0.005'
x-x402-amount: '5000'
x-payment-info:
protocols:
- x402
price:
mode: fixed
currency: USD
amount: '0.005'
x-audience: business
x-sample-url: https://agents.writerslogic.com/api/v1/samples/tax-id-format
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- items
properties:
items:
type: array
minItems: 1
maxItems: 100
items:
type: object
required:
- value
properties:
value:
type: string
minLength: 1
maxLength: 40
description: With or without the country prefix; spaces, dots and hyphens are ignored.
country:
type: string
pattern: ^[A-Za-z]{2}$
description: ISO 3166 alpha-2 (EU VAT prefix). Optional when the value carries its prefix.
example:
items:
- value: ATU13585627
- value: DE 136 695 978
- value: FR40303265045
responses:
'200':
description: Paid result with provenance
content:
application/json:
schema:
type: object
properties:
data:
type: object
properties:
status:
type: string
enum:
- pass
- fail
- unknown
- unsupported
description: 'pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.'
results:
type: array
items:
type: object
properties:
index:
type: integer
country:
anyOf:
- type: string
- type: 'null'
normalized:
anyOf:
- type: string
- type: 'null'
scheme:
anyOf:
- type: string
- type: 'null'
checks:
type: array
items:
type: string
description: 'Checks actually run for this country: format and/or checksum.'
status:
type: string
enum:
- pass
- fail
- unknown
- unsupported
checkDigit:
anyOf:
- type: object
properties:
expected:
type: string
actual:
type: string
- type: 'null'
counts:
type: object
description: Items per status.
properties:
pass:
type: integer
fail:
type: integer
unknown:
type: integer
unsupported:
type: integer
witnesses:
type: array
items:
type: object
properties:
ruleId:
type: string
detail:
type: string
path:
type: string
description: JSON pointer or dotted path into the input.
offset:
type: integer
index:
type: integer
expected:
description: What the rule required.
actual:
description: What the input had.
versions:
type: object
description: Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
limits:
type: array
items:
type: string
deterministic:
type: boolean
description: 'Always true: pure code, no model.'
_provenance:
type: object
description: C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance
required:
- data
- _provenance
'400':
description: Invalid request (no payment consumed)
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
'401':
description: Invalid X-API-KEY
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
'402':
description: Payment required or invalid
content:
application/json:
schema:
type: object
description: x402 v2 PaymentRequired (also base64 in the PAYMENT-REQUIRED header)
properties:
x402Version:
type: integer
error:
type: string
code:
type: string
resource:
type: object
accepts:
type: array
items:
type: object
extensions:
type: object
'502':
description: Upstream failure; the payment is released or not settled
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
tags:
- Tax Id Format
components:
securitySchemes:
x402:
type: apiKey
in: header
name: PAYMENT-SIGNATURE
description: x402 v2 payment payload (base64) sent after a 402 challenge
apiKey:
type: apiKey
in: header
name: X-API-KEY